It is known practice to those skilled in the art to incorporate capacitive presence sensors in the gripping lever of handles of opening sections of motor vehicles.
This makes it possible to detect the presence of an object such as a hand of a user of the motor vehicle when it is about to grasp the gripping lever of the handle in order to open the opening section, and thus to initiate the unlocking of said opening section.
The approach of the finger or of the hand of the user toward the electrode of the capacitive sensor varies its capacitance.
The capacitive sensor is generally linked to a management unit which triggers the locking or the unlocking of the opening section as a function of the information delivered by the electrode, that is to say as a function of the variation of capacitance thereof.
One drawback is that such a capacitive sensor comprises an electrode sensitive to the capacitance value of the environment. Thus, when this sensor is arranged in a gripping lever of a handle which has a decorative conductive element, for example on the outer face of this lever, the sensitivity of the electrode is reduced by the presence of this decorative conductive element. The decorative conductive element thus varies the electrical field of the sensor. When the hand passes over the front face of the gripping lever of the handle, it is then considered to be inside the handle and therefore interpreted as an action of the user to lock or unlock the opening section.
Similarly, in a rain shower, a trickle of water may run over the handle. In this case in point, the capacitance of the electrode varies also and this variation is interpreted wrongly by the management unit as an action by the user to lock or unlock the opening section.
Also, according to another prior art known to those skilled in the art, to remedy these drawbacks, a capacitive presence sensor arranged in the gripping lever of a handle of an opening section of a motor vehicle has been proposed that comprises:                a first electrode for measuring capacitance defining a first detection zone and a second electrode for measuring capacitance defining a second detection zone;        a so-called guard plane capable of minimizing a capacitive coupling between said first electrode and said second electrode; andsaid sensor being linked to a processing unit connected to said first electrode, to said second electrode and to the guard plane, said processing unit being suitable for periodically and alternately setting said guard plane at the same potential as said first electrode or at the same potential as said second electrode.        
The two measurement electrodes are arranged at right angles to one another, one being oriented toward the opening section of the vehicle, namely toward the zone where a hand has to be detected, and the second being oriented toward the top part of the gripping lever of the handle, the part which may receive a decorative conductive element.
In order to arrange them at right angles to one another, the second electrode (or lateral electrode) which is a bi-electrode is an add-on part. It consists of a pair of welded metal barrels. Consequently, a signal processing must be performed to make it possible to separate the capacitive information items originating from each of the electrodes.
One drawback with such a capacitive sensor is that it is bulky and that it requires an add-on component which makes it mechanically fragile. Moreover, if the sensor incorporates a low-frequency antenna, the performance thereof is reduced by the spurious effect of the add-on part on the antenna.
In this context, the present invention aims to resolve the abovementioned drawback.